missing help and support center

I recently encountered a problem after trying to download drivers for a laptop. This happened on my desktop. After downloading anything I typically run malwarebytes to check for problems and run an antivirus scan. When I tried to run malware bytes anti malware it would not start. I tried to update it and the update would not complete. The icon disappeared from my desktop and the program itself no longer appears in my programs. So I tried to run McAfee and it will not run. It gets to the scan page and stalls at "undefined %". So I tried to access help and support to roll the machine back to before I downloaded the drivers and help and support is no longer there. When I click on help and support I get this message... Windows cannot find helpcenter.exe.

I tried to use my xp service pack 2 disk to reinstall and or repair files and this did not work. I also tried helpctr -regserver to no avail. I also downloaded IOBit malware fighter and ran a scan and it came back negative.

Any help would be greatly appreciated!

Robert

Dell Dimension 4550 P4 2.4Ghz 2GB memory. Windows XP sp3 McAfee antivirus.